Uniform illumination for camera based scanning devices

Abstract

A system for imaging a document including an imaging apparatus, which includes a camera positioned inside the imaging apparatus, the camera configured to acquire a plurality of images of a document in front of the camera. The document is place behind a glass window on a wall opposing the camera. The imaging apparatus includes an illumination system which is positioned around the glass window but outside the field of view (FOV) of the camera. The imaging apparatus further includes an opaque cover, which covers the whole glass window area. The cover includes a slit to insert a document to be imaged, a slit to remove the document and a groove that enables a user to move the document with his finger.

1. An imaging apparatus used in conjunction with a processor in a camera system for imaging a document, the imaging apparatus comprising:
 (a) a camera, having a lens-ocular with a predetermined field of view (FOV), said camera configured to acquire a plurality of image frames of at least a portion of the document; 
 (b) a camera-chamber, wherein said camera is disposed inside said camera-chamber; 
 (c) an enclosed optical-chamber; 
 (d) a camera-wall having a camera-face, an optical-face and an ocular-opening formed in said camera-wall at a preconfigured location, said camera-wall being a mutual wall of said optical-chamber and said camera-chamber, wherein said lens-ocular fits inside said ocular-opening, and wherein said optical-face faces said optical-chamber; 
 (e) a window-wall positioned opposite to said camera-wall, said window-wall having an internal face and an external face, wherein the document is operatively disposed adjacent to said external face; 
 (f) a substantially transparent window integrated into said window-wall, wherein said transparent window is viewed by said FOV of said lens-ocular; and 
 (g) at least one light source configured to operatively illuminate the document, 
 
       wherein said at least one light source is disposed inside said optical-chamber but outside said FOV of said lens-ocular, thereby said at least one light source cannot directly illuminate said lens-ocular of said camera. 
     
     
       2. The imaging apparatus of  claim 1 , wherein the document is an identity document. 
     
     
       3. The imaging apparatus of  claim 1 , wherein said at least one light source is disposed on said internal face of said window-wall, distal from said transparent window, thereby said at least one light source cannot directly illuminate the document. 
     
     
       4. The imaging apparatus of  claim 1 , wherein said at least one light source is an infra red light source, an ultra violate light source or a fluorescence image. 
     
     
       5. The imaging apparatus of  claim 1 , wherein said at least one light source is a LED light source. 
     
     
       6. The imaging apparatus of  claim 1 , wherein said at least one light source includes a light diffuser for even illumination of the document. 
     
     
       7. The imaging apparatus of  claim 1 , wherein said at least one light source includes a light diffuser which is a light reflector. 
     
     
       8. The imaging apparatus of  claim 1 , wherein said at least one light source includes a light diffuser being is a light reflector and including a light baffle for preventing direct illumination of the document by said light source. 
     
     
       9. The imaging apparatus of  claim 1 , wherein all walls of said optical chamber are opaque, except for said transparent window. 
     
     
       10. The imaging apparatus of  claim 1 , wherein the document is operatively disposed adjacent to said transparent window, on said external face of said window-wall. 
     
     
       11. The imaging apparatus of  claim 1 , wherein the imaging apparatus further comprising:
 (h) an opaque cover, said cover covering at least said transparent window area. 
 
     
     
       12. The imaging apparatus of  claim 11 , wherein said cover is securely attached to said external face of said-window wall and forms a gap between said transparent window and said cover, said cover comprising:
 (a) a slit formed at the top part section of said cover for inserting the document; 
 (b) a slit formed on at least one side of said cover to facilitate removal of the document; and 
 (c) a document moving mechanism for moving the document disposed in said gap formed between said transparent window and said cover. 
 
     
     
       13. The imaging apparatus of  claim 12 , wherein said document moving mechanism is a groove formed in said cover, and wherein the document can be moved by a user's finger or by an article, inserted through said groove. 
     
     
       14. The imaging apparatus of  claim 13 , wherein said groove is formed in said cover such that when the document is imaged by said camera, the documents blocks light from being transmitted in and out of the imaging apparatus, through said groove. 
     
     
       15. The imaging apparatus of  claim 1 , wherein said at least one light source of said illumination system is operable to emit visible light. 
     
     
       16. The imaging apparatus of  claim 15 , wherein said optical-face of said camera-wall is substantially white, thereby illumination diffused from said optical-face of said camera-wall is substantially white.